diff --git a/mu4e/mu4e-headers.el b/mu4e/mu4e-headers.el
index bdd0ec8e..302c60cf 100644
--- a/mu4e/mu4e-headers.el
+++ b/mu4e/mu4e-headers.el
@@ -256,7 +256,7 @@ only marks the first message in the thread.")
 (defvar mu4e-headers-thread-child-prefix '("|>" . "│ ")
   "Prefix for messages in sub threads that do have a following sibling.")
 (defvar mu4e-headers-thread-first-child-prefix '("o " . "⚬ ")
-  "Prefix for messages in sub threads that do not have a following sibling.")
+  "Prefix for the first child messages in a sub thread.")
 (defvar mu4e-headers-thread-last-child-prefix '("L" . "└ ")
   "Prefix for messages in sub threads that do not have a following sibling.")
 (defvar mu4e-headers-thread-connection-prefix '("|" . "│ ")